ast_coredumper running as root sources ast_debug_tools.conf from /etc/asterisk; potentially leading to privilege escalation

Asterisk is an open source private branch exchange and telephony toolkit. Prior to versions 20.7-cert9, 20.18.2, 21.12.1, 22.8.2, and 23.2.2, the asterisk/contrib/scripts/ast_coredumper runs as root, as noted by the NOTES tag on line 689 of the ast_coredumper file. The script will source the contents of /etc/asterisk/ast_debug_tools.conf, which resides in a folder that is writeable by the asterisk user:group. Due to the /etc/asterisk/ast_debug_tools.conf file following bash semantics and it being loaded; an attacker with write permissions may add or modify the file such that when the root ast_coredumper is run; it would source and thereby execute arbitrary bash code found in the /etc/asterisk/ast_debug_tools.conf. This issue has been patched in versions 20.7-cert9, 20.18.2, 21.12.1, 22.8.2, and 23.2.2.